The persistent, and recently rising, stunting rate in West Sumatra, Indonesia, from 23.3 percent in 2021 to 24.9 percent in 2024, still above the national average of 19.8 percent, signals a failure of current policy approaches rather than of national commitment. Most Indonesian stunting research explains this persistence through household-level determinants such as sanitation, maternal education, and feeding practices, leaving the design of the policies themselves under-examined. This study addresses that gap by treating policy design, not household behavior, as the object of analysis. Its contribution is methodological: it applies Jasser Auda's seven-element Maqasid Framework, concepts, purposes, values, commands, universal laws, groups, and proofs, for the first time as a diagnostic instrument for subnational stunting governance in a Muslim-majority, customary (adat) society, rather than as a purely normative or theological tool. Drawing on qualitative fieldwork in Solok and West Pasaman districts, document analysis of local regulations and in-depth interviews and observations with policymakers, health cadres, and community members, the study maps local stunting policies onto the seven Maqasid elements and finds a systemic lack of synergy among them: technically narrow concepts detached from a shared higher purpose, marginalized Minangkabau customary leadership (tungku tigo sajarangan), and implementation reduced to bureaucratic routine. The study concludes that meaningful progress requires reorienting stunting governance from fragmented, target-driven administration toward purpose-driven, culturally embedded policy design, positioning the Maqasid Framework as a transferable diagnostic and design tool for comparable development challenges.